The present invention relates to a method and/or architecture for die placement on a substrate generally and, more particularly, to rotating the die to minimize die-to-die routing complexity.
Conventional multi-die semiconductor packages are organized internally about Cartesian coordinates. Dies are mounted to a substrate with the die sides aligned along an imaginary X-Y grid. Traces on the substrate carrying inter-die signals are also aligned along the imaginary X-Y grid with some corners being shortened by 45 degree routes. One consequence of the imaginary X-Y grid is that some traces on the substrate follow long and complex routes. The long and complex routes cause signal propagation delays, add to fabrication expenses, reduce reliability, and contribute to crosstalk.
A typical approach to reducing routing complexity is to align two dies so that high priority inter-die traces route between parallel facing sides of the dies. The resulting traces are short and straight thus contribute little to propagation delays and crosstalk. The parallel facing side approach is effective only when the high priority inter-die signals bonding pads are on only one side of each die. In situations where the high priority signal bonding pads are scattered across two or more die sides, then the signals of the non-facing sides must be routed over longer, more complex traces.
The present invention concerns a method of fabricating a semiconductor package that may contain two or more dies. The method generally comprises the steps of (A) mounting a first die having a first side on an assembly apparatus and (B) mounting a second die having a second side and an adjoining third side on said assembly apparatus. The second die may be oriented such that (i) the second side and the third side both face the first side and (ii) the second side and the third side are both substantially nonparallel to the first side.
The objects, features and advantages of the present invention include providing a method and architecture for mounting two dies on an assembly apparatus that may (i) reduce inter-die connection complexity, (ii) increase inter-die communication speeds, (iii) increase reliability, and/or (iv) reduce crosstalk.